package com.zetcode;

import java.io.IOException;

import java.nio.ByteBuffer;

import java.nio.channels.Channels;

import java.nio.channels.ReadableByteChannel;

import java.nio.channels.WritableByteChannel;

import java.nio.file.Files;

import java.nio.file.Paths;

public class ChannelCopy {

public static void main(String[] args) throws IOException {

var srcFile = Paths.get("src/resources/beginning.txt");

var destFile = Paths.get("src/resources/beginning2.txt");

try (var src = Channels.newChannel(Files.newInputStream(srcFile))) {

try (var dest = Channels.newChannel(Files.newOutputStream(destFile))) {

copyBytes(src, dest);

}

}

}

private static void copyBytes(ReadableByteChannel src,

WritableByteChannel dest) throws IOException {

var buf = ByteBuffer.allocateDirect(1024);

while (src.read(buf) != -1) {

// flip the buffer from read to write

buf.flip();

// Make sure that the buffer was fully drained

while (buf.hasRemaining()) {

dest.write(buf);

}

buf.clear();

}

}

}